Local equivalence ratio measurement of CH4/air and C 3H8/air laminar flames by laser-induced breakdown spectroscopy

Yuji Ikeda, Atsushi Nishiyama, Nobuyuki Kawahara, Eiji Tomita, Takashi Nakayama

Research output: Chapter in Book/Report/Conference proceedingConference contribution

13 Citations (Scopus)


The local equivalence ratios of CH4/air and C3H 8/air mixtures were measured using a laser-induced breakdown spectroscopy technique with a fiber-coupled ICCD spectrometer with Cassegrain optics. Localized breakdown plasma was generated from the pulse of a Q-switched Nd:YAG laser with a wavelength of 532 nm. This system allowed us to measure laser-induced plasma spectra with high spatial and temporal resolution. The specified intensity ratio and set up equivalence ratios were well correlated and found to be a good indicator in practical measurement. The intensity ratio indicated a remarkable relationship regardless the presence of the flame. For the unburned and burned regions, there were some differences in the change in the intensity ratio, but the calibration slopes were almost similar. It was found that this technique can measure the local equivalence ratio of methane or propane premixed laminar flame regardless a flame. The intensity ratio was not a function of the incident beam intensity or flow rate, which is very acceptable for practical measurement. In this experiment, the relative error was around 5%.

Original languageEnglish
Title of host publicationCollection of Technical Papers - 44th AIAA Aerospace Sciences Meeting
Number of pages13
Publication statusPublished - 2006
Event44th AIAA Aerospace Sciences Meeting 2006 - Reno, NV, United States
Duration: Jan 9 2006Jan 12 2006

Publication series

NameCollection of Technical Papers - 44th AIAA Aerospace Sciences Meeting


Other44th AIAA Aerospace Sciences Meeting 2006
Country/TerritoryUnited States
CityReno, NV

ASJC Scopus subject areas

  • Space and Planetary Science
  • Aerospace Engineering


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